From: "Serge E. Hallyn" Subject: Re: [RFC][PATCH 2/4] sunrpc: Use utsnamespaces Date: Tue, 6 Jan 2009 18:01:32 -0600 Message-ID: <20090107000132.GA22261@us.ibm.com> References: <20090106011314.534653345@us.ibm.com> <20090106011314.961946803@us.ibm.com> <20090106200229.GA17031@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Matt Helsley , Linux Containers , linux-nfs@vger.kernel.org, Linux Kernel Mailing List , Trond Myklebust , "J. Bruce Fields" , "Eric W. Biederman" , Linux Containers , Cedric Le Goater To: Chuck Lever Return-path: Received: from e38.co.us.ibm.com ([32.97.110.159]:34202 "EHLO e38.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752388AbZAGABf (ORCPT ); Tue, 6 Jan 2009 19:01:35 -0500 In-Reply-To: Sender: linux-nfs-owner@vger.kernel.org List-ID: Quoting Chuck Lever (chuck.lever@oracle.com): > On Jan 6, 2009, at Jan 6, 2009, 3:02 PM, Serge E. Hallyn wrote: >> Quoting Matt Helsley (matthltc@us.ibm.com): >>> We can often specify the UTS namespace to use when starting an RPC >>> client. >>> However sometimes no UTS namespace is available (specifically during >>> system >>> shutdown as the last NFS mount in a container is unmounted) so fall >>> back to the initial UTS namespace. >> >> So what happens if we take this patch and do nothing else? > > I thought the point of this was to prevent incorrect container nodenames > from leaking onto the network. But define incorrect. If container B does an nfs mount, container c is launched with a tree in that mount, container B dies, and container C umounts it. Should the umount belong to container B (for having mounted it), container C (for having umount it), or the init_utsname (for being the physical host/kernel)? I get the feeling that consensus on this thread is that init_utsname is actually the best choice, but OTOH if I have 3 containers on my host, for apache, mysql, and postfix servers, and each is doing nfs mounts from a physically remote machine, maybe I care about having them report separate nodenames? (that's a question, I really don't know...) -serge